Gas control unit



H. J. PARDEE GAS CONTROL UNIT June 6, 1933.

Filed F b, 10, 1931 4 Sheets-Sheet 1 gnue nfo'a Howard Pardee Q1 m i June 1933. H J PARDEE 1,912,383

GAS CONTROL UNI T Filed F b, 10, 1931 4 Sheets-Sheet z 7 s 4 @1211 a l Howard Jana-e6 3% ammo/IL H. J. PARDEE GAS CONTROL UNIT June 6, 1933.

Filed Feb, 10, 1931 4 Sheets-Sheet 3 gwuentoz Howard E'lrdee Pom/MK H. J. PARDEE GAS CONTROL UNIT June 6, 1933.

4 Sheets-Sheet 4 Filed Feb. 1

INVENTOR Howard J. Pardee BY a- MC ATTORNEYS.

Patented June 6, 1933 UNITED STATES HOWARD J. PARDEE, OF NEW YORK, N. Y.

GAS CONTROL UNIT Application filed February 10, 1931. Serial No. 514,884.

The present invention relates to a gas control unit which, in its broadest aspect, is of general application. However, the invention has a particular relation to that type of gas control unit which is adapted to maintain and control a flow or feed of gas from a source of supply to a body of Water, sewage, or the like material to be treated.

The primary object of the instant invention is to maintain an exact flow of gas and to have this exact flow easily adjustable within the limits of the device. To do this, a gas control unit is provided which is capable of performing two functions: (a) maintain a uniform adjustable flow and maintain this flow at an exact pressure or density. This latter is necessary because the higher the pressure of a gas in a device of the type in question the more it is compressed and the more actual gas will flow through the unit.

Among the many other objects of the present invention are the following:

(a) To provide a new and improved gas control device which shall include a compact and efiicient arrangement of gas compensator, meter, back pressure valve and gauges in a single portable unit;

(6) To provide a new and improved gas control unit of the character described which shall include a novel form of self-cleaning inlet valve;

(0) To provide an improved inlet valve construction in a unit of the character described, which shall be so related to its operating diaphragm as to substantially eliminate errors due to friction in operation;

(d) To provide a new and improved method and means for screwing the inlet valve device of a gas control unit of the instant type onto and from its diaphragm;

(c) To provide, in a gas control unit, a novel and improved meter for determining the rate of flow through the unit; and

(f) To provide a novel gas control unit having an improved back end, that is, discharge valve and operating diaphragm.

The foregoing and other objects, which will be apparent to those skilled in the art to which this invention pertains from the detailed de- 0 scription below, are attained by the embodiments of the invention hereinafter disclosed, consisting of the construction and novel combination and arrangement of parts fully described below, illustrated in the accompanying drawings and pointed out in the several claims hereunto appended.

In the accompanying drawings,

. Fig. 1 represents, somewhat diagrammatically, a view, partly in section and partly in elevation, of the unit constituting the present invention, a portion of the meter being broken away;

Fig. 2 represents, somewhat diagrammatically, a sectional detail of the inlet valve assembly; 1

Fig. 3 is a view of one end of the inlet valve seat container;

Fig. 4 is a View of the other end of the inlet valve seat container;

Fig. 5 is a view of the slotted end of the inlet valve spring container;

Fig. 6 represents, somewhat diagrammatically, a sectional detail of the control valve of the present invention;

Fig. 7 represents, somewhatdiagrammatically, a sectional detail of an orifice meter adapted to be used in connection with the present invention;

Fig. 8 represents, somewhat diagrammatically, a sectional detail of a bubbling meter adapted to be used with this invention;

Fig. 9 represents, somewhat diagrammatically, a sectional detail of the discharge valve assembly;

Fig. 10 is an elevational cw of the back diaphragm reinforce; and

Fig. 11 is a view, partly in section and partly in elevation, of one form of gauge.

Similar reference characters indicate cor- 9o responding parts throughout the several views.

Referring now to the drawings, and particularly to Fig. 1 thereof, it will be seen that the gas control unit constituting this inven- 5 tion comprises elementally:

(a) An inlet manifold A. This leads from the gas tanks, cylinders or other source of supply.

(6) A tank-pressure gauge B. This indicates the pressure of the gas available in the supply.

(0) An inlet valve C. This functions, as hereinafter explained, to cut down the pressure from the supply cylinders to a certain relative pressure on the inlet to the control valve E. The pressure in the supply cylinders is continuously fluctuating. If it is not cut down to a constant value the unit will not maintain the flow of gas for which it is set, but

will feed more or less gas as the pressure in the cylinders changes.

(d) A front diaphragm D. This automatically works the inlet valve C, opening and closing it as required.

(6) A control valve E. This the amount of gas fed.

f) A front pressure gauge F. This 1nd1- cates the pressure to which the gas has been reduced by the inlet valve G.

(g) A meter G. This shows the amount of gas flowing through the unit, and 15 used to set the feed and check its maintenance.

(h) A back diaphragm H. This automatically works the discharge valve J.

(j) A discharge valve J. The discharge valve takes care of the different pressures on the discharge side of the unit. These pressures vary just as the supply pressure does, and such changes would change the flow of gas if uncompensated. The discharge valve J holds the gas back to a constant pressure, back pressure, which is higher than any pressure against which the unit must work. It also acts as a check valve to keep water from getting back into the unit, flooding it, and causing corrosion and fouling.

(7c) The back pressure gauge K. This 1ndicates the pressure at which the discharge valve J is holding the unit.

These several parts are attached to, supported by, or depend from the casing of the unit which is made up of the front plate 1, middle plate 2, and back plate 3, all suitably secured together.

The inlet valve assembly (Figs. 2, 3, 4 and 5) The front plate 1 is formed centrally and forwardly thereof (to the right in Fig. 1) with a hollow cylindrical boss or extension 4. The outer end of the extension 4 is closed in gas-tight relationship by the valve seat conregulates tainer 5. This container. together with a manifold nipple 6, are securely held to the extension 4, by means of the inlet valve nut 7, as shown. The valve seat is shown at 8.

Disposed adjacent the inner end of the extension'4 is the front diaphragm D which is supported on the diaphragm d1sk 9. Screw-threadedly engaging an opening disposed centrally of the disk 9 is the diaphragm center 10 which terminates in an exteriorlythreaded cylindrical portion 11 extending toward the seat container 5.

A substantially cylindrical valve-spring container 12 is mounted upon the extension 11, and terminates in the inwardly-turned end 13. The end 13 is slotted, as at 14, for a purpose hereinafter described.

Extending from the diaphragm center 10 through the containers 12 and 5 and valve seat 8, is the valve stem 15. The stem 15 is positively held to the diaphragm D, as follows: a V-wire 16 extends through an opening in the lower end of the stem 15, and a safety spring 16 is disposed between a washer 17, adjacent the V-wire 16, and the end 13 of the spring container.

This arrangement gives an extremely great sensitivity and accuracy and at the same time makes possible a pull of 15,000 pounds per square inch pressure on the seating surfaces of the valve, by taking advantage of the large area of the diaphragm D. The valve spring 16 acts only when the pull on the stem 15 becomes so great that the latter is endangered. With this arrangement the stem 15 moves positively with the diaphragm without any outside friction.

The inlet valve C comprises the first small opening in the control unit. Any impurities or fouling coming from the supply cylinders will plug this valve first. To protect against this, the stem 15 of the valve passes through the seat 8. Its continual slight back and forth movement tends to work any fouling through the valve into the adjacent larger space where there is plenty of room for it. With this arrangement large amounts of fouling have been found in the space inside the valve altho no irregularity of operation has been observed.

The middle plate 2 is formed centrally thereof with a rearwardly extending substantially cylindrical boss or extension 18, closed at its rear end. The front spring 19 is disposed in the extension 18, extending between the rear end of the latter and the diaphragm disk 9.

According to this invention, novel means is provided for removing and replacing the inlet valve on its diaphragm. Because of the close quarters, there is no way to get in at the spring container 12 to screw it onto the diaphragm. To overcome this difficulty, the outer end of the spring container 12 is provided with slots 14, and the inner end of the seat container 5 is provided with lugs 20 adapted to engage the slots 14.

To remove the inlet valve, the gas is turned ofl and the manifold A and nut 7 are removed. When the gas pressure is released, the diaphragm D moves, under the urge of spring 19, to a forward position about ggnds to th of an inch from the normal operating position shown in Fig. 2. Lengths of slots 14 and lugs 20 are so controlled that when diaphragm D is in its forward position, they are adapted to engage each other to the extent of between fi th and 5nd of an inch. The container 5 is now rotated and the valve unscrewed and removed.

To replace the valve, it is inserted in place in the extension 4. The lugs 20 on the seat container 5 are then caused to engage the slots 14. Rotation of the seat container 5 causes the spring container to rotate and to be screwed onto the diaphragm, the latter being in its forward position. When the container 12 reaches home, the lugs 20 and slots 14 interengage to the extent of from 5nd to th of an inch. When the gas is subsequently turned on, its pressure pushes the diaphragm D back to its working position. This movement draws the spring container 12 entirely clear of the lugs 20 on the seat container 5, so that during operation of the unit there is absolutely no contact and no possible friction between the two.

The control valve (Fig. 6)

The control valve E regulates the amount of gas fed through the unit. For this purpose a very fine adjustment is obviously advantageous.

The control valve E preferably comprises a valve seat 21 and stem 22. The latter is packed as at 23, and the packing as well as a cylindrical thread-piece 24, are securely held in place by the packing nut 25. The handle 26 of the valve is constructed with differential threads 27, 28 to provide micrometer adjustment. These differential threads consist of an internal thread 28 which engages the stem 22, and an external thread 27 engaging the thread piece 24:. One. complete revolution does not move the stem 22 a full thread but only the difference between the two thread pitches since one thread screws out as the other screws in. By using a small difi'erence in pitch, a very fine adjustment is obtained.

For larger capacities, a regular needle stem is preferably used in the control valve E. For the small capacities, the end of the stem 22 is preferably a small straight rod fitting tightly into the end of its coacting valve seat; This rod is provided with a sloping V notch in one side. The triangular opening gives much steadier flows, and it is harder to plug than the minutely narrower circular slot of the needle stem at small flows.

Theorifice meter (Fig. 7)

The orifice meter G functions to show how much gas is passing through the gas control unit.

The meter comprises a meter case 29 which is securely suspended from the back plate 3 through the medium of the meter connection nut 30. Gas-tight relationship is secured by the use of gaskets, as shown. The meter G further includes an orifice assembly 31, the orifice preferably being anopening 32 in the wall of thelatter.

Supported from the orifice assembly 31 is the inner tube 33 which telescopes into the outer tube 34, suitably mounted 1n the meter case 29. As illustrated, the upper part of the outer tube 34 is preferably 0 larger crosssectlon than the lower art. Holding the inner tube 33 to the ori ce assembly is the large square packing nut 35.

he entire meter may be unscrewed as a whole from the rest of the unit b unscrewmg the meter connection nut 30. Then, if the meter is to be disassembled (as for cleaning), the manometer liquid 36 may be poured out. The split ring 37 which is mounted in the nut 30 is then snapped out, and the nut 30 slipped down over the meter case 29. The orifice holder 31 with the inner tube attached thereto is then withdrawn. If the orifice holder 31 is stuck to the case 29, a knife blade may be inserted therebetween to separate them.

As heretofore described, the packing nut 35 around the inner tube is square and the corners of this square now come into close contact with the case 29 so that when the orifice assembly 31 is raised, it cannot be moved sideways until after this nut is above the end of the case 29, so making a side motion which might break the inner tube 33 impossible during the time the assembly 31 is being loosened from any sticking to the case 23. There is a certain tendency to tip the orifice assembly 31 sideways in getting it loose, which tipping may result in the breaking of the inner tube, and which the packing nut 35 prevents.

In operation, the gas flows in at the top of the inner tube 33, through the orifice 32, and up and out of the meter, as indicated by the arrows in Fig. 7. To push the gas thru the orifice 32 the pressure in the inner tube 33 is greater than in the outer tube 34.- This greater pressure in the inner tube not only pushes the gas through the orifice but it also pushes the liquid 36 in the inner tube below the level of the liquid in the outer tube. The more gas flowing thru the orifice 32, the greater is the difference in pressure and the farther the'inner liquid level is depressed below the outer liquid level. By measuring the depression, the amount of gas flowing through the unit can be determined. The meter scale 38 functions to show the amount of gas flowing through the unit by measuring the difference in the liquid levels.

The back pressure is important when reading the meter. The scale 38 is marked for a certain back pressure. If the back pressure is higher, the gas is more compressed and more weight goes through the meter than the scale shows. If the back pressure is low, less gas passes than the scale indicates. The proper back pressure is marked on the scale 38 and the discharge pressure.

5 manometer liquid 36 to be used, which is important where the gas being measured is soluble in the liquid, as is usually the case. As the gas dissolves in the liquid 36, the liquid volume increases and this raises the liquid level in the meter. If the outer tube 34 is large all the way down, the amount of increase in volume due to the solution of gas may change the level of the surface several inches, but if most of the length of the tube 34 is of small area while the top thereof is of large area, the change in the level of the surface due to the solution of the gas will not vary much.

The bubbling meter (F 2'9. 8)

This is an alternative form of meter. The purpose of this meter is, like the orifice meter G, to show how much gas is flowing through the unit.

The construction of the upper end of the bubbling meter is substantially identical with the upper end of the orifice meter G, except that there is no orifice 32 in the member 31, the sole outlet leading to the inner tube 33. The latter includes enlarged upper and lower portions 39 and 40 connected by a constricted portion 41. A bubbling lip 42 is provided at the lowermost end of the inner tube 33. The meter case 29 has a peep opening or window 43 therein, and the little glass teat 44 on the tube 33' should be visible through the window 43 to insure that the high edge of the bubbling lip 42 is disposed directly in front thereof In operation, the gas flows down through the inner tube 33, bubbles from the lip 42 of the bell 40, rises through the meter liquid 36, and passes from the top of the outer tube 34 to the discharge valve J.

The rate at which the gas is passing through the meter is indicated by the number of bubbles coming away from t e bottom of the inner tube every minute. The amount of gas passing for any rate of bubbling can be obtained from a calibration table. Care must be taken that the back pressure is that called for on the table and that the meter liquid is that specified otherwise the bubbles will be a different size and the amounts given in the table incorrect.

The liquid 36 should be only enough above the lower bell 40 to allow the bubbles to be easily seen. The purpose of the enlargement 40 is to trap any meter liquid from working back into the unit.

The discharge 'valre (F 598. 9 wrwl 10) The discharge valve assembly J is mounted in a rearwardly protruding hollow boss or exbly and the back diaphragm assembly constitute the back end of the gas control unit.

The valve assembly comprises a valve seat 46 which is carried on the longitudinally movable seat container 47. Movement of the latter, with consequent adjustment of the seat 46, is effected by rotation of the valve handle 48. Packing nut 49 securely holds the device in place on the extension 45, and gas-tight relationship is maintained by the packing 50.

The valve stem 51 has its inner end screwed into the back diaphragm center 52 which, in turn, is in threaded engagement with the disk center 53. The back diaphragm H is supported and reinforced by the flexible disk 54. Since, in operation, pressure up to 150 pounds per square inch may come on one side of the diphragm against only atmospheric pressure on the other side, a strong diaphragm is necessary. Yet the diaphragm must be very flexible. To accomplish this, a light diaphragm H is used, with the reinforcement 54 behind it. The reinforcing disk 54 is slotted, as at 55, to give the effect of a plurality of segments, but the slots do not quite reach the outer edge of the disk 54, ending in holes 56 having sufiicient stock between them and the edge of the disk 54 to act as a weak spring. This disk 54 moves in and out at its center just as a grou of individual segments would, and has the a vantage of a single piece which can be assembled without the possibility of displacement of the individual segments.

In usual back pressure valves of this type which use segments, the pressure of the valve spring has been brought to the center of the diaphragm. It has not rested upon the segments. Such an arrangement results in the pressure on the individual segment acting as a beam between the casing and the center of the diaphragm. Since the center of area of the segment is approximately two-thirds of the way from the center to the casing, approximately two-thirds of the pressure against the segment goes to the reaction at the casing end and only one-third to the reaction at the center end where the valve stem is operated and the pressure of the spring comes. In addition, the pressure at the reaction points at the ends of the segments results in considerable friction at these points. Such a a valve must have a relatively high spring pressure, for errors due to the friction at the reaction points are relatively high in respect to this spring.

According to the present invention, the segments of the reinforce 54 are supported by a disk 57 having a knife edge 58 around its edge, and the diameter of this knife edge is such that it passes through the center of area of the segments. This arrangement means that the total pressure of gas against the diaphragm H is transmitted through this circular knife edge 58 of the disk 57 to the tension 45 of the back plate 3. This assemback spring 59. There is theoretically no SDO reaction at the ends of the se ments and therefore no friction errors. g hat slight friction may arise is absorbed in the back spring 59 which is three times as strong as a spring for the same size diaphragm w ere the spring pressure is brought to the center of the diaphragm. The difference in accuracy between this method of applying the spring pressure and the method where the pressure is taken to the center of the diaphragm, is very great.

The reinforce 57 is provided with bent-up ears 60 for correctly positioning the knife edge 58.

The back spring 59 extends from the spring piece 57 to middle plate 2 around the exten sion 18 of the latter. This arrangement of diaphragms H and D back to back and nested springs 19 and 59 permits a compactness, the advantages of which are obvious. It saves parts and cost, eliminates joints with their tendency to leak, and due to the compactness, allows the attachment of the whole device directly to the gas supply cylinder, adapting it for portable operation.

The discharge valve J by remaining nearly closed holds back the gas in the unit to maintain a uniform back pressure or density. This results in a uniform weight of gas passing through the unit. The amount of back pressure is adjusted by turning the handle 48 in or out. This indirectly compresses orreleases the back spring 59.

The usual arrangement is to increase or decrease the tension on the spring from the spring end. According to the present invention, adjustment of the spring 59 is from the opposite end of the device, making it possible to put the spring end in an interior position to attain compactness.

The pressure gauge (Fig. 11)

In Fig. 11, one embodiment of pressure gauge is shown. The gauge 61 is protected by the usual silver diaphragm 62. The gauge and the space above the diaphragm 62 are completely filled with a liquid. The pressure of the gas against the diaphragm 62 is transmitted by this liquid to the gauge. A liquid trap 63 below the gauge diaphragm catches and holds any leak. The port 64 leading to the diaphragm is covered by a metal cap 65 to prevent piercing of the diaphragm when cleaning the port 64 With a wire or nail.

Operation In operation, the gas enters through the inlet manifold A and the supply pressure is registered on the tank pressure gauge B. It then flows through the inlet valve C, across the front of the front diaphragm D, registering this pressure 'on the front pressure auge F, through the control valve E, across the back of the front diaphragm D, to, down into and up out of the meter G, across the back of the back diaphragm H registerin this pressure on the back pressure gauge and dischar es from the unit through the discharge va ve J.

As heretofore mentioned, the pressure maintained in the unit is called the back pressure. Its maintenance is independent of the operation of the rest of the unit. It is accomplished by the back diaphragm H and discharge valve J. The spring 59 behind this diaphragm keeps the discharge valve J closed until the gas pressure 1n the unit builds up to a certain point. This built-up pressure then pushes the diaphragm H and spring 59 forward and opens the discharge valve J enough to allow the gas to discharge, and the pressure can go no higher. If, however, the pressure starts to fall, the spring 59 pushes the diaphragm H back and closes the valve enough to maintain the pressure. Gas cannot get through the unit below the pressure that opens the discharge valve J, and it cannot be at a higher pressure or the discharge valve will open wider and relieve it. In operation, the back diaphragm H is pushed forward and the discharge valve J opened just enough to allow a steady flow of gas to discharge while it is held in the unit at the exact density or pressure desired.

The back pressure is indicated on the back pressure gauge K. It can be adjusted by turning the handle on the discharge valve J. The latter is designed to give plenty of pres sure to overcome any resistance in the dis charge line.

The rate of flow of gas through the unit 1s adjusted by opening and closing the control valve E. It is maintained by accurately maintaining a constant difference between the pressure on the inlet and outlet of this valve. This difference is the pressure which pushes the gas through the valve. If it is constant, the flow will be constant.

The ever changing supply pressure and possible slight changes in back pressure must be overcome to accomplish this. Control is obtained by the front diaphragm D and inlet valve C. The pressure on the inlet to the control valve E is on the front of the diaphragm D, the pressure on the discharge on its back. In addition the push of the spring 19 is on its back. The combined push of spring 19 and back pressure on the back must equal the push of the front pressure on the front, or the diaphragm D will move. This will open or close the inlet valve 0. If the back pressure and spring 19 are stronger, the diaphragm moves forward. This opens the inlet valve C and lets in more gas until the front pressure 'has built up to the balance. If the front pressure is too strong, the diaphragm D is pushed back. This throttles the inlet valve C until the front pressure has dropped to balance.

Whatever condition is set up, the diaphragm D and inlet valve C will move and change the flow of gas into the unit until the front pressure has increased or decreased to equal whatever the back pressure is plus the push of the spring 19. Changes in back ressure are met by an exactly equal change in front pressure. Changes in supply pressure result in the inlet valve G opening or closing just a little to maintain the balancing front pressure under the new conditions. But whatever happens the difference in pressure stays the same.

This difference between the front and back pressures is the push of the spring 19. Since this spring push is always constant, the pressure difference is constant and flow of gas through the control valve is constant.

The arrangement of the front and back diaphragms D and H according to the present invention as above disclosed results in very accurate and dependable control of the flow of gas. It consists of but a few parts and so has the advantage of simplicity. By having the diaphragms sufiiciently large there is plenty of power. Springs 19 and 59 are proportioned well within their strength so that they remain absolutely constant.

While the present invention has been described above in some detail, it is to be understood that various minor changes may be made therein without departing from the spirit of the same.

I claim:

1. A gas control unit of the character described comprising a casing, an inlet valve for admitting gas to said casing, a discharge valve for discharging gas, and independent means for operating each of said valves, each of said means comprising a spring-controlled diaphragm, and said springs being disposed in internested relationship within said casmg.

2 A gas control unit of the character described comprising, in combination, a front plate, a middle plate, and a back plate definmg a casing, a hollow extension protruding rearwardly from said middle plate, a front diaphragm disposed between said front and middle plates, a back diaphragm disposed between said back and middle plates, a front d aphragm spring extending from said front diaphragm to the interior of said extension, and a back diaphragm spring extending from said back diaphragm around said extension, whereby said springs are nested one within the other.

3. In an inlet valve assembly for use in a gas control unit of the character described, a valve spring container and a juxtaposed valve seat container, the end of said spring container adjacent said seat container being provided with slots, and lugs on the juxtaposed end of said seat container adapted to align with and engage said slots.

4. In a device of the character described, in combination, a casing, a forwardly-pro jecting extension in the front of said cas-' ing, an inlet valve in said extension, an opera-ting diaphragm for said inlet valve, and a spring acting on the back of said diaphragm, a rearwardly-projectin extension in the back of said casing, a disc arge valve in said second-named extension, an operating diaphragm for said discharge valve, and a spring acting on the back of said secondnamed diaphragm, substantially as described.

5. A gas control unit of the character described comprising a casing, an inlet as for admitting gas to said casing, a ischarge valve for discharging said gas, independent means for operating each of said valves, said discharge valve including a diaphragm operatively connected thereto, a longitudinally movable valve seat container, a valve seat in said container, and a valve stem, and means for adjusting said discharge valve by moving said valve seat container.

6. In a device of the character described, in combination, a diaphragm, a valve spring container adapted to threadedly engage said diaphragm, a valve seat container, a valve stem extending between said spring container and seat container, and coacting means on adjacent ends of said containers whereby said spring container may be threaded into and out of engagement with said diaphragm.

7. The combination defined in claim 6, and a hollow cylindrical boss surrounding said containers in close adjacence thereto.

HOWARD J. PARDEE. 

